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Vitamin K the basics--what's new?

Frank R Greer1

  • 1Department of Pediatrics, University of Wisconsin School of Public Health and Medicine, Madison, WI, USA. frgreer@pediatrics.wisc.edu

Early Human Development
|February 2, 2010
PubMed

Insights

Vitamin K status in infants is not well understood, impacting hemorrhagic disease risk. Preterm infants show high vitamin K levels, warranting further study of vitamin K epoxide reductase (VKOR).

Area of Science:

  • Biochemistry
  • Neonatology
  • Nutritional Science

Background:

  • Hemorrhagic disease of the newborn remains a global concern, with limited understanding of vitamin K needs in term and preterm infants.
  • Perinatal vitamin K transfer from mother to infant is minimal, making neonatal sources crucial.
  • Neonatal vitamin K sources include prophylaxis, diet, and gut bacteria, with preterm infants receiving substantial amounts from medical interventions.

Purpose of the Study:

  • To review vitamin K metabolism, its dependent proteins, and the vitamin K cycle in infants.
  • To explore the importance of vitamin K for human health, particularly in preterm infants.
  • To investigate the implications of elevated vitamin K serum concentrations in preterm infants.

Main Methods:

  • Review of existing literature on vitamin K metabolism and neonatal sources.
  • Analysis of vitamin K status in term and preterm infants based on current data.
  • Examination of vitamin K-dependent proteins and the vitamin K cycle in the neonatal context.

Main Results:

  • Little vitamin K crosses the placenta, and neonatal sources are limited.
  • Preterm infants exhibit significantly higher vitamin K serum concentrations compared to adults and term infants.
  • Elevated vitamin K epoxide reductase (VKOR) in preterm infants' serum is noted, though no toxicity has been reported.
  • PIVKA-II is not a reliable marker for vitamin K deficiency in neonates.

Conclusions:

  • Further research is needed on vitamin K requirements and the significance of elevated VKOR in preterm infants.
  • Current understanding of vitamin K metabolism and status in neonates requires further investigation.
  • Clinical indicators for vitamin K deficiency in infants may need re-evaluation.

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